Just about all the LA in my area buy from Marshall's Dry Goods. Hobbs 80/20 on a big roll. Marshall's has a lot of different ones but Hobbs seems to be the favorite. The rough airy poly is awful, what is that stuff used for anyway?
You don't have to have a tax number to buy wholesale, just have to buy from a rep there, not the shop. Pick a rep and call. He/she will be your rep for anything wholesale from the store and who you will call to order anything or who you will buy from at the store. You can buy from the store too but it's all cut yardage.